The Pitch Drip Dripped ‘Round the World

A science experiment 69 years in the making has finally come to a conclusion at Dublin’s Trinity College. Though this may seem like small potatoes compared to the 421-year-old university, scientists are thrilled that the experiment—a test of the viscosity of the plant byproduct pitch—has come to fruition.

So, why is this a big deal? Back in 1944, the experiment was started by a colleague of Nobel Prize winner Ernest Walton at the Trinity physics department. His aim was to prove that the black carbonic substance was indeed viscous or flowing (this had long been hypothesized, but there wasn't any actual proof). Over the years, a few drips were said to have fallen into the jar—the last was recorded on November 28, 2000—but the evidence had never before been captured on camera until last week. Based on the results of the experiment, they can now estimate the viscosity of pitch to be two million times that of honey.

Professor Shane Bergin of TCD School of Physics called the long-awaited event “amazing,” saying it summed up why he likes being a scientist—science serving as a catalyst for curiosity. Until its 69-year-old hypothesis was fulfilled, many physicists believed the experiment to be among the oldest active experiments in the world. The title for the world’s longest running experiment is a similar study started in Australia in the 1920s—another jar of pitch, one that has not yet been caught dripping on camera.